I changed mine to a 180 and I have had no problems. I can tell you it only takes about 1 to 1.5 hrs to do. Yes, the intake has to come off, linkage clips, and a couple other clips by the throttle bodies. You will have to unclip the harnesses to the fuel injection system in the back of the head by the drivers side. The hardest part is holding the intake close to the engine while you clip all the harnesses back to the bottom of the intake. If you are a do it yourselfer, its not a hard thing to do. When you pull the intake you have to move it forward to get the gas line disconnected and it will shoot gas due to the pressure but not much. Before you restart the engine, turn the key on for a few seconds, then cut it off, then back on for a few more seconds so that gas is fully pumped up to through the line to the injectors. When you go to put the intake back on you have to have someone hold it while you place the intake gaskets on and connect the connectors to the bottom of the intake, then set the intake in place and retorque the bolts, which are very easy to get to. The job is really pretty easy. Actually easier than the gen 1 which you cant even see in the rear of the motor. You must make sure you burp all the water out, or plan on a overheated engine. I did my 98 rt about 6 months ago with no problems, and damm glad I did it. The thermostat can be bought from NAPA and stant is the maker. Its a 190 that has been modified by stant. E-mail me if you have any questions.